Some horseshoe pits contain sand. Although the minimum depth of material in a horseshoe pit is four inches, eight inches is recommended for professional tournament play. Loose dirt, clay and synthetic compositions are also legal. The purpose of the pit material is to hold the shoe in place when it lands. Two types of sand are found in the pits.
Kid’s Play Sand
Most horseshoe courts that contain sand use the play sand usually found in children's sandboxes. This sand is usually made of granite, which contains a little quartz that gives it a sparkly look. Builders pour sand into the pit to within one inch of the height of the edges of the pit. As some of the sand flies out of the pit and the remaining sand tamps down during play, more sand must be added at times.
In order to keep the sand in the pits, horseshoe pits that contain play sand must be dampened and dressed at the end of practically every inning. This is the maintenance process of leveling the surface by kicking and smoothing the sand after the horseshoes have been removed from the playing area.
Some private outdoor horseshoe pits contain utility sand, which is commonly used in landscaping. A bit heavier than play sand, utility sand holds up and stays in the pit area better than its counterpart. This sand is gravelly and rough, and tends to be slippery when dry. It also must be lightly sprinkled with water during play.
Clay as a Sand Alternative
Most horseshoe pits used in tournament play are filled with moist blue clay rather than sand. This is because the horseshoes can "stick" in place better once they land in clay than they do in sand. Blue clay, also known as soapstone or blue shale, is superior to red clay because, unlike red clay, it does not build up on horseshoes and does not have a slippery feel to it.
Other Sand Alternatives
Many backyard horseshoe pit owners prefer loose dirt in their pits. They use the dirt already in the pit area by digging out the first two to four inches of dirt then returning up to three inches back into the pit. The dirt must be continually maintained to keep it loose in all sections of the pit area. Synthetic materials may also replace sand in horseshoe pits, especially in indoor pits.